Multiple electrical terminal connector for panelboards and/or load centers



I June 2, 1970 c. GOODRIDGE 3,516,049

MULTIPLE ELECTRICAL TERMINAL CONNECTOR FOR PANELBOARDS AND/OR LOAD CENTERS Filed June 12, 1968 2 Sheets-Sheet 1 mum/r01? LA wRn/ce C Goon/was ATTORNEY J1m 1970 L. c. GOODRIDGE 3,516,049

MULTIPLE ELECTRICAL TERMINAL CONNECTOR FOR PANELBOARDS AND/OR LOAD CENTERS Filed June 12, 1968 2 Sheets-Sheet? FIGQIZ /IV VEN TOR L A wen/c5 C Goon/ewes United States Patent 3,516 049 MULTIPLE ELECTRICAL TERMINAL CONNECTOR FOR PANELBOARDS AND/0R LOAD CENTERS Lawrence C. Goodridge, Bristol, C0nn., assignor to General Electric Company, a corporation of New York Filed June 12, 1968, Ser. No. 736,472 Int. Cl. H011 7/12 US. Cl. 339-242 8 Claims ABSTRACT OF THE DISCLOSURE A multiple electrical terminal connector for electrical panelboards and/or load centers comprising a strip of conductive material having a plurality of spaced semiloops formed therein, an elongated support member of a high mechanical strength low cost metal such as steel having a plurality of spaced projecting portions engaging the strip and holding it in juxtaposed relation to the support member, and a plurality of clamping screws threaded into the support member for retaining in place wire conductors positioned in the aforesaid semi-loops.

BACKGROUND OF THE INVENTION Field of the invention My invention relates to multiple electrical terminal connector assemblies, and more particularly to multiple electrical terminal connectors for use in electrical panelboards and/ or load centers to provide means for connection of ground wires of branch lighting and power circiuts to the main power line ground.

Description of the prior art In accordance with the prior art, multiple terminal connectors for electrical panelboards have been generally of two basic types. The first of these has involved the use of a conductive plate and terminal screws and wire retaining cup washers to make the wire connections. In the other type, a conductive member is provided having a generally rectangular cross-section with the wire conductors extending into holes in a side wall and being retained by means of clamping screws in holes suitably provided in the top wall.

A basic disadvantage of both of these types of terminal connectors is their cost. The first type is costly because of the material and labor involved in installing the retaining washers, while the second type is costly because of the substantial amount of relatively expensive conductor material required in the connector. Another undesirable feature is that although the first type of terminal connector is the less costly of the two types, its applicability is limited by the existence of electrical code requirements which limit the size of wire with which it may be used.

The second type of terminal connector generally is of two basic designs, those which have the entire housing made of a conductor material, and those which have a tubular housing of low conductivity material with a conductive bar inserted into it. The first design of this type uses a high-cost conductive material for both the electrical and mechanical functions of the terminals. The second design uses a straight bar of a conductor material only for the electrical function and a low conductivity material for the mechanical function. In doing so however the second design has sacrificed quality for cost and has certain inherent application limitations such as the fact that it is very difiicult to pass the Underwriters Laboratory test with this design for use with aluminum wire.

3,516,049 Patented June 2, 1970 OBJECTS OF THE INVENTION boards which is simple in construction, easy to assemble,-

and inexpensive to manufacture.

Another object of the present invention is to provide a multiple terminal connector for electrical panelboards which provides for maxi-mum contact between the wire conductors and the conductor portion of the connector thereby affording excellent electrical contact therebetween as well as good resistance to pull-out forces exerted on the wires.

A still further object of the present invention is to provide such a multiple terminal connector having improved heat transferring capabilities between the wire conductors and the connector.

Yet another object of the present invention is to provide such a multiple terminal connector which may be used in present designs of panelboards and load centers without requiring any substantial modification in such panelboards and load centers.

SUMMARY OF THE INVENTION In accordance with the present invention there is provided a multiple terminal connector having a sandwich type construction comprised of two elongated members of dissimilar materials clamped together in juxtaposed relation. The first of these two members consists of a relatively narrow 'bar or strip of conductive material having a plurality of semi-loops formed therein along the length thereof in closely spaced relation relative to each other, each for the purpose of receiving a wire conductor. The second of the members comprises a relatively narrow bar of a high mechanical, low cost, essentially low conductivity material which is provided with a plurality of spaced tabs or integral projections. The tabs are suitably positioned in the spaces between the semi-loops of the first member to thereby securely clamp the two members together. The wire conductors are clamped in the semi-loops by means of screws threaded into openings suitably provided therefor in the layer of low conductivity material. The length of the screws is limited to not more than a predetermined magnitude to ensure that the wire conductors will not be severed as a result of overtightening the aforesaid screws.

The invention will be more fully understood from the following detailed description and its scope will be pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of a multiple terminal connector assembly constructed in accordance with the present invention;

FIG. 2 is a side elevation view of the terminal connector assembly of FIG. 1;

FIG. 3 is a perspective view of one of the multiple terminal connectors illustrated in FIGS. 1 and 2 in accordance with the present invention;

FIG. 4 is a bottom view of one of the terminal connectors illustrated in FIGS. 1 and 2 in accordance with the present invention.

FIG. 5 is a sectional view through one of the terminal connectors illustrated in FIGS. 1 and 2;

FIG. 6 is a sectional view of a portion of the terminal connector of FIG. 5, taken substantially on the section indicated by the line 66 of FIG. 5;

FIG. 7 is. a side elevation view of another embodiment of a terminal connector in accordance with the present invention;

FIG. 8 is a sectional view of the terminal connector of FIG. 7 taken substantially on the section indicated by the line 8-8 of FIG. 7;

FIG. 9 is a side elevation view of another embodiment of a terminal connector in accordance with the. present invention;

FIG. 10 is a sectional view of the terminal connector of FIG. 9, taken substantially on the section indicated by the line 10'10= of FIG. 9;

FIG. 11 is a plan view of another terminal connector assembly embodying terminal connectors in accordance with the present invention; and

FIG. 12 is a side elevation view of the terminal connector assembly of FIG. 11.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to FIG. 1, the invention is shown as embodied in a multiple terminal connector assembly 10 comprising an insulating base 11, and a plurality of terminal connectors 12, a main lug 13, and a conductor 14, all supported on the base 11.

The insulating base 11 which is preferably of molded construction has a pair of protective end barriers 16 and 17, a front wall 18, and a back wall 19. Each of the protective end barriers 16 and 17 is provided with a pair of spaced rib portions 16a, 16b, and 17a, 17b, respectively which are formed integrally therewith to provide three separate substantially non-interconnecting channels 20, 2 1 and 22 in the end barriers 16, 17. Extending outwardly from the end barriers 16 and 17 in perpendicular relation thereto adjacent the channels 20, 21, and 22 are members 23, 24, and 25 formed as an integral part of the insulating base 11, which cooperate with the rib portions 16a, 16b, 17a, and 17b to provide the insulating base 11 with a step-like internal construction.

Protruding from the rear of back wall 19 in spaced relation are a pair of bosses 26 and 27, each having therein an opening 26a, 27a, respectively, capable of receiving appropriate fastening means (not shown) to detachably secure the insulating base 11 of the terminal connector assembly 10 to bus bars (not shown) in a panelboard or load center (not shown).

Referring now to FIGS. 3 and 4, the terminal connector 12 employed with the terminal connector assembly 10 of FIGS. 1 and 2 consists of a substantially U-shaped channel member 28, and a 'bar 29 of good conductive material such as copper or aluminum formed to provide a plurality of wire receiving semi-loops 30 therein. In the form illustrated in FIG. 3, the bar 29 is constructed by extruding a member having a number of parallel channels and then slicing or cutting the member to provide pieces as shown.

The channel member 28 is preferably of a strong, lowcost material such as steel and may be of relatively low conductivity or even non-conductive, since it is not required to carry current. The member 28 has a plurality of threaded openings 32 along the center portion thereof. The bar 29 of conductive material is also provided at one end thereof with an opening 33 for a purpose to be described hereinafter.

Referring to FIG. 4, it can be seen that the spacing between the tabs 31 is such that when the U-shaped channel member 28 and the bar 29 are brought into juxtaposed relation such that the respective openings 3-2a and 33 therein are aligned, each of the tabs 31 will lie adjacent the space existing between adjoining semi-loops 30 in the bar 29. To secure the member 28 and the bar 29 together, the tabs 31 are bent around the underside of the bar 29 whereby intimate continuous contact is provided between the member 28 and the bar 29. It has been found in actual use that even though the mechanical layer, i.e., the U-shaped channel member 28, is made from a relatively low conductivity material such as steel, it will carry some current thereby permitting the use of a smaller size conductive layer, i.e., a smaller size bar 29.

With the member 28 and the conductive bar 29 so assembled, each of the semi-loops 30 is capable of receiving a conventional wire conductor (not shown). The semicircular shape of the loops 30 in the conductive bar 29 provides almost the maximum amount of contact possible between the wire conductor and the bar 29. There is thus provided excellent electrical contact therebetween as well as good resistance against the pull-out forces exerted on the wire conductors.

In accordance with the preferred embodiment of the invention, screws 34 are utilized to retain the wire conductors in the semi-loops 30'. The screws 34 are threaded in the tapped holes 32 provided therefor at spaced intervals in the center portion of the U-shaped channel member 28. The openings 32 are suitably spaced along the member 28 such that when the member 28 and the bar 29 are in the. assembled condition, one of the openings 32 will be aligned with each of the semi-loops 30. The member 28 provides increased mechanical strength for the screw threads although in accordance with the preferred embodiment of the invention the screws 34 are. themselves made of a high strength, low cost material which may be of relatively low conductivity, such as steel. It has been found to be unnecessary to provide the semi-loops 30 with pre-cut threads for receiving the set screws 34 when the latter are threaded into the openings 32. Instead, the dimensions of the semi-loops and of the screws are so chosen that when the screws 34 are tightened they form partial threads in the side wall portions of the semi-loops 30. This occurs by virtue of the fact that the material of which the bar 29 is made is relatively soft as compared to the material from which the screws 34 are formed.

As seen in FIG. 6, the point 34a of the screw 34 is rounded to prevent it from creating an excessive Weakening in the wire conductor when the screw is tightened onto the wire conductor. In addition, the length of the screw 34 is controlled such that the head 34b of the screw will seat against the top surface of the member 28 surrounding the opening 32 before the screw 34 can be overtightened thereby preventing excessive distortion or weakening of the wire conductor.

Insofar as the manufacture of the terminal connector 12 is concerned, the U-shaped channel member 28 is preferably formed by a simple stamping process with the openings 32 and 32a therein being provided in a subsequent manufacturing step. The bar 29 as noted previously is cut to the proper width from a sheet of extruded conductor material, the semi-loops having been already formed in the sheet during the extrusion process. The opening 33 is thereafter provided in one end of the bar 29. The terminal connector 12 may then be readily assembled in the manner previously set forth, i.e., by bending the tabs 31 inwardly along the underside of the bar 29 in the spaces existing between the semi-loops 30.

In accordance with the modification in the terminal connector 12' which is illustrated in FIGS. 7 and 8 of the drawings, the bar 29' is provided with a pair of elongated slots 29a and 29b, respectively, which extend along the entire length of the bar 29' adjacent the underside of the center portion thereof. The slots 29a and 29b are provided for the purpose of receiving the tabs 31 which in accordance with this modification of the invention when bent inwardly are positioned in the aforesaid slots rather than in the spaces existing between the semi-loops 30' as described previously with regard to the terminal connector 12 illustrated in FIGS. 3, 4, 5, and 6.

To assemble the member 28 and the bar 29' of FIGS. 7 and 8, the tabs 31 are first bent inwardly, and then the bar 29 is slid along between the underside of the center portion of the member 28' and the tabs 31 until the openings (not shown) in the member 28 are in alignment with the semi-loops 30' in the bar 29' in the manner previously described in connection with the terminal connector 12. With screws (not shown) positioned in the respective openings in the member 28', the bar 29' is prevented from moving out of its proper position relative to the member 28'.

FIGS. 9 and 10 illustrate another embodiment 35 of a terminal connector which includes a flat strip 36 of conductive material having a plurality of threaded openings 37 provided therein at spaced intervals along the length thereof. In addition, the terminal connector 35 includes an inverted channel-shaped member 38 having a plurality of spaced semi-loops 39 which are lanced out of the center portion of the member 38. The member 38 also is pro vided with continuous side wall flange portions 38a and 38b, respectively, bent inwardly toward each other in spaced relation to the center portion of the member 38, with the flange portions 38a and 38b being substituted for the plurality of spaced tabs 31 provided in the terminal connector 12 of FIGS. 3, 4, 5, and 6. To assemble the component parts of the terminal connector 35', the flat strip 36 is slid along between the flange portions 38a, 38b, and the center portion of the channel-shaped member 38 until an opening 37 in the flat strip 36 is aligned with each of the semi-loops 39 in the member 38. With screws (not shown) threaded into the openings 37 provided in the flat strip 36 and into the semi-loops 39, the flat strip 36 will be kept properly positioned relative to the channel-shaped member 38.

Referring again to FIGS. 1 and 2 of the drawings, the terminal connector assembly 10 as illustrated therein includes the maximum number, i.e., a total of six, terminal connectors 12. The connectors 12 are arranged in pairs, with each pair thereof being offset vertically and horizontally from the remaining two pairs of terminal connectors 12. To mount the terminal connectors 12 on the insulating base 11, the end portion of each of the terminal connectors which does not have the openings 32, 33 therein is slid into a notch 40 suitably provided in one of the channels described hereinbefore which are formed in the protective end barriers 16 and 17 of the insulation base 11.

The other end of each of the terminal connectors 12 cooperates with the conductor 14 which has a double Z- shape, i.e., step-like, configuration. The conductor 14 is positioned approximately midway between the end barriers 16 and 17, and in juxtaposed relation to each of the three steps formed in the base 11. The horizontally extending portions of the conductor 14 which overlie the steps of the base 11 are suitably provided with a pair of threaded openings (not shown) whereby with the conductor 14 positioned on the base 11 as seen in FIGS. 1 and 2, the opening 32a, 33 in each of the terminal conductors '12 will be aligned with one of the threaded openings provided in the conductor 14.

Suitable fastening means such as the screws 41 and the washers 42, the former being received in the opening 32a, 33 of each of the lowermost pair, as viewed in FIG. 2, of terminal connectors 12 and in the cooperating openings in the conductor 14, are utilized to fasten the lowermost terminal connectors 12 to the conductor 14, and the latter in turn to the insulating base 11. The terminal conductors 12 positioned in the middle step of the base 11 as viewed with reference to FIG. 2 are similarly secured by suitable fastening means to the conductor 14, and the latter also to the base 11.

Referring particularly to FIG. 1 of the drawings, the uppermost pair of terminal connectors 12 overlie the leg portion 13a of the main lug 13, which in turn overlies the horizontal portion of the conductor 14 which is positioned in juxtaposed relation to the upper step of the insulating base 11. Screws 43 which are received in the openings 32a, 33 of the terminal connectors 12, the openings (not shown) provided for this purpose in the leg portion 13a, and the previously described threaded openings (not shown) in the conductor 14, are employed to secure the terminal connectors 12, the main lug 13, and the conductor 14 to the base 11. Thus, as described hereinabove, the terminal connectors 12 are all mechanically secured to the base 11, and by virtue of the conductor 14 which is common to all the terminal connectors 12 are electrically interconnected with each other and with the main lug 13.

As seen with reference to FIGS. ll and 12 of the drawings, only one terminal connector 12 is utilized in the terminal connector assembly designated therein by the reference numeral 10. The only modification in the terminal connector assembly 10' necessitated by this over that of the terminal connector assembly 10 as shown in FIGS. 1 and 2 is the replacement of the main lug 13 of terminal connector assembly 10 with a conductive spacer 44 and a lug 45 which is of smaller dimension as compared to main lug 13 and does not include any portion corresponding to the leg portion 13a of lug 13. In the terminal connector assembly 10', the terminal connector 12 is secured to the spacer 44 by means of screw 43', and the spacer 44 is secured through the conductor 14 to the base 11 in a manner similar to that previously described in connection with the terminal connector assembly 10 of FIGS. 1 and 2. It will be noted that here also the conductor 14 electrically interconnects the terminal connector 12, spacer 44, etc.

FIGS. 11 and 12 also illustrate another form of terminal connector 46 being utilized in the terminal connector assembly 10'. The connector 46 is comprised of a flat strip 47 of conductive material upon which are mounted a limited number of lugs similar to the lug 45 referred to hereinabove. Terminal connectors of this latter type are generally required when using fairly large size wire conductors.

As illustrated in FIGS. 11 and 12, however, terminal connectors 12 are compatible for use in combination with other forms of terminal connectors such as for example that designated by reference numeral 46, or when fewer than the maximum number. of terminal connectors capable of being employed in a particular terminal connector assembly are required for a given job installation.

While certain preferred embodiments of the invention have been specifically disclosed, it will be understood that I do not wish the scope thereof to be limited thereto since many modifications thereof may readily be made.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A multiple terminal connector comprising:

(a) a first generally planar elongated member;

(b) a second generally planar elongated conductive member having a plurality of generally U-shaped offset portions intermediate the ends thereof closely spaced in a row along the length thereof, each of said U-shaped portions including a pair of parallel leg portions and a connecting bight portion and defining a wire-receiving passageway extending substantially at right angles to the length of said strip;

(c) means supporting said second elongated member in juxtaposed face-to-face parallel relation to said first elongated member with predetermined portions of said first elongated member bridging the space between said leg portions of said U-shaped portions at the ends thereof opposite said bight portion; and

(d) wire retaining screws threaded into said predetermined portions of said first member for retaining wire conductors in said U-shaped portions of said second member.

2. A multiple terminal connector as set forth in claim 1 wherein:

(a) said first elongated member is of relatively low conductivity, high strength material; and

(b) said second elongated member is of relatively high conductivity material.

3. A multiple terminal connector as set forth in claim 1 wherein said supporting means comprises a plurality of tabs formed on said first elongated member engaging said second elongated conductive member at spaced points along the length thereof.

7 8 4. A multiple terminal connector as set forthin'claim ((1) Wire retaining screws threaded into said prede- 1 wherein: termined portions of said first elongated conductive (a) said first elongated member is of relatively low member for retaining wire conductors in said U- conductivity, high strength material; shaped portions of said second elongated member. (b) said second elongated member is of relatively 5 7. A multiple terminal connector as set forth in claim high conductivity material; and 6 wherein: (c) said supporting means comprises a pair of in- (a) said first elongated member is of relatively high wardly bent flange portions formed on said first conductivity material; elongated member engaging said second elongated (b) said second elongated member is of relatively conductive member, 10 low conductivity, high strength material; and 5. A multiple terminal connector as set forth in claim (0) said supporting means carried by said second 4 wherein; elongated member comprises a pair of inwardly id l ti l l w d ti it high t n th bent fiange portions formed on said second elongated terial i t el; nd member engaging said first elongated conductive (b) said relatively high conductivity material is alumimember. 7

mum 8. A multiple terminal connector as set forth in claim 6. A multiple terminal connector comprising: 7 whereifll a fi t generally planar elongated conductive (a) said recllatively high conductivity material is aluminum; an

ber;

(b) a second generally planar elongated member hava plurality of generally U-shaped offset portions intermediate the ends thereof closely spaced in a row along the length thereof, each of said U-shaped portions including a pair of parallel leg portions and (b) said relatively low conductivity, high strength material is steel.

References Cited UNITED STATES PATENTS a connecting bi ht portion and defining a wire-re- I 9 9 10/1959 Daley 339-272 iving assageway extending substantially at right 2909757 10/1959 Speck, 339 198 angles to the length of said strip; gig g g 851966 Sturdwan 317 119 d b d 1 t d 5, 2 1 1969 Walter et a1. 33922 (C) means carrl y Sal secon conga e nlember Stand] supporting said first elongated conductive member in uxtaposed face-to-face parallel relation to said sec- RICHARD MOORE, Primary Examiner ond elongated member with predetermined portions of said first elongated conductive member bridging MCGLYNN Asslstant Examlner the space between said leg portions of said U-shaped U S C1 R portions at the ends thereof opposite said bight portion' and 339 272 

